diff --git a/include/server/response.h b/include/server/response.h
new file mode 100644
index 0000000..d930bb4
--- /dev/null
+++ b/include/server/response.h
@@ -0,0 +1,45 @@
+#ifndef SERVER_RESPONSE_H
+#define SERVER_RESPONSE_H
+
+#include "types.h"
+
+void res_null_req(mg_connection* conn);
+void res_must_get(mg_connection* conn);
+void res_must_post(mg_connection* conn);
+void res_need_token(mg_connection* conn);
+void res_auth_fail(mg_connection* conn);
+void res_check_exist_fail(mg_connection* conn);
+void res_user_exist(mg_connection* conn);
+void res_not_exist(mg_connection* conn);
+void res_check_permission_fail(mg_connection* conn);
+void res_permission_denied(mg_connection* conn);
+void res_need_user_id(mg_connection* conn);
+void res_need_password(mg_connection* conn);
+void res_(mg_connection* conn);
+void res_(mg_connection* conn);
+void res_(mg_connection* conn);
+void res_(mg_connection* conn);
+
+
+void res_delete_account_fail(mg_connection* conn);
+void res_delete_account(mg_connection* conn);
+
+void res_login_fail(mg_connection* conn);
+void res_incorrect(mg_connection* conn);
+void res_login(mg_connection* conn, const char* token);
+
+void res_register_fail(mg_connection* conn);
+void res_register(mg_connection* conn);
+
+void res_repasswd_fail(mg_connection* conn);
+void res_repasswd(mg_connection* conn);
+
+void res_logout_fail(mg_connection* conn);
+void res_logout(mg_connection* conn);
+
+void res_(mg_connection* conn);
+void res_(mg_connection* conn);
+void res_(mg_connection* conn);
+void res_(mg_connection* conn);
+
+#endif
\ No newline at end of file
diff --git a/src/server/response.c b/src/server/response.c
new file mode 100644
index 0000000..5cfc9f0
--- /dev/null
+++ b/src/server/response.c
@@ -0,0 +1,203 @@
+#include "server/types.h"
+#include <server/response.h>
+
+#include <civetweb.h>
+
+void res_null_req(mg_connection* conn)
+{
+    mg_printf(conn,
+              "HTTP/1.1 400 Bad Request\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"error\":\"null request\"}");
+}
+void res_must_get(mg_connection* conn)
+{
+    mg_printf(conn,
+              "HTTP/1.1 405 Method Not Allowed\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"error\":\"must send get request\"}");
+}
+void res_must_post(mg_connection* conn)
+{
+    mg_printf(conn,
+              "HTTP/1.1 405 Method Not Allowed\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"error\":\"must send post request\"}");
+}
+void res_need_token(mg_connection* conn)
+{
+    mg_printf(conn,
+              "HTTP/1.1 400 Bad Request\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"error\":\"need token\"}");
+}
+void res_auth_fail(mg_connection* conn)
+{
+    mg_printf(conn,
+              "HTTP/1.1 401 Unauthorized\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"error\":\"auth failed\"}");
+}
+void res_check_exist_fail(mg_connection* conn)
+{
+    mg_printf(conn,
+              "HTTP/1.1 500 Internal Server Error\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"error\":\"failed to check user existence\"}");
+}
+void res_user_exist(mg_connection* conn)
+{
+    mg_printf(conn,
+              "HTTP/1.1 409 Conflict\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"error\":\"user already exists\"}");
+}
+void res_not_exist(mg_connection* conn)
+{
+    mg_printf(conn,
+              "HTTP/1.1 404 Not Found\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"error\":\"user does not exist\"}");
+}
+void res_check_permission_fail(mg_connection* conn)
+{
+    mg_printf(conn,
+              "HTTP/1.1 500 Internal Server Error\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"error\":\"failed to check user permission\"}");
+}
+void res_permission_denied(mg_connection* conn)
+{
+    mg_printf(conn,
+              "HTTP/1.1 403 Forbidden\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"error\":\"permission denied\"}");
+}
+void res_need_user_id(mg_connection* conn)
+{
+    mg_printf(conn,
+              "HTTP/1.1 400 Bad Request\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"error\":\"need user_id\"}");
+}
+void res_need_password(mg_connection* conn)
+{
+    mg_printf(conn,
+              "HTTP/1.1 400 Bad Request\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"error\":\"need password\"}");
+}
+void res_(mg_connection* conn);
+void res_(mg_connection* conn);
+void res_(mg_connection* conn);
+void res_(mg_connection* conn);
+
+
+void res_delete_account_fail(mg_connection* conn)
+{
+    mg_printf(conn,
+              "HTTP/1.1 500 Internal Server Error\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"error\":\"failed to delete account\"}");
+}
+void res_delete_account(mg_connection* conn)
+{
+    mg_printf(conn,
+              "HTTP/1.1 200 OK\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"success\":\"delete account success\"}");
+}
+
+void res_login_fail(mg_connection* conn)
+{
+    mg_printf(conn,
+              "HTTP/1.1 500 Internal Server Error\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"error\":\"failed to login\"}");
+}
+void res_incorrect(mg_connection* conn)
+{
+    mg_printf(conn,
+              "HTTP/1.1 401 Unauthorized\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"error\":\"incorrect password or user id\"}");
+}
+void res_login(mg_connection* conn, const char* token)
+{
+    mg_printf(conn,
+              "HTTP/1.1 200 OK\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"success\":\"login success\", \"token\":\"%s\"}",
+              token);
+}
+
+void res_register_fail(mg_connection* conn)
+{
+    mg_printf(conn,
+              "HTTP/1.1 500 Internal Server Error\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"error\":\"failed to register\"}");
+}
+void res_register(mg_connection* conn)
+{
+    mg_printf(conn,
+              "HTTP/1.1 200 OK\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"success\":\"registration success\"}");
+}
+
+void res_repasswd_fail(mg_connection* conn)
+{
+    mg_printf(conn,
+              "HTTP/1.1 500 Internal Server Error\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"error\":\"failed to repasswd account\"}");
+}
+void res_repasswd(mg_connection* conn)
+{
+    mg_printf(conn,
+              "HTTP/1.1 200 OK\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"success\":\"repasswd account success\"}");
+}
+
+void res_logout_fail(mg_connection* conn)
+{
+    mg_printf(conn,
+              "HTTP/1.1 500 Internal Server Error\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"error\":\"failed to logout\"}");
+}
+void res_logout(mg_connection* conn)
+{
+    mg_printf(conn,
+              "HTTP/1.1 200 OK\r\n"
+              "Content-Type: application/json\r\n"
+              "Access-Control-Allow-Origin: *\r\n\r\n"
+              "{\"success\":\"logout success\"}");
+}
+
+void res_(mg_connection* conn);
+void res_(mg_connection* conn);
\ No newline at end of file